Time-setting device

ABSTRACT

For programmed control of an on-off switch provided with a first cam fixedly mounted on a shaft so as to operate the switch according to its angle of revolution. A second cam is similarly mounted on the shaft which is rotatably supported in the adjacency of the switch, the second cam selectively conveying to the first cam the rotation which proceeds in step with the lapse of time. Additional means are provided for selectively imparting rotation to the first cam through the shaft.

O United States Patent 1 1 1 1 3,729,601 Yokoyama et al. 1 Apr. 24, 1 973 [54] TIME-SETTING DEVICE 2,858,387 10/1958 Crimmins ..200/38 B [75] Inventors: Etsuzo Yokoyama, Tachikawa-shi, 2943l59 6/1960 sooihouse et ZOO/33 B Yasuva 0on0 Nakano ku both of 3,180,157 4/1965 Harris ..200/38 A 3,225,151 12/1965 Lagasse ...200/38 A X Tokyo Japan 3,521,442 7/1970 Umezawa ..200/38 R x [73] Assignees: Kabushiki Kaisha T.I.O.; Hitachi, Limited both of Tokyo-to, Japan P mary ExaminerJ. R. Scott [22] Filed: Sept. 14, 1971 Attorney-15. F. Wenderoth et a1. [21] Appl. No; 180,265 [57] ABSTRACT For programmed control of an on-off switch provided [52] US. Cl. ..200/38 R, ZOO/35 R with a fir t cam fixedly mounted on a shaft so as to [51] Int. Cl. ..HOlh 7/08, HOlh 43/10 Operate h it h according to its angle of revolution. [58] Field of Search ..200/33 B, 37 A, 38, A Second Cam is similarly mounted on h h ft which 200/35 R; 74/35, 3.52, 3.54, 3.56; 568 is rotatably supported in the adjacency of the switch,

the second cam selectively conveying to the first cam [56] References C'ted the rotation which proceeds in step with the lapse of UNITED STATES PATENTS time. Additional means are provided for selectively impartmg rotation to the first cam through the shaft. 3,188,409 6/1965 Linn... ..200/38 B 3,598,2' l4 8/197 1 Harris ..200/38 R X 8 Claims, 8 Drawing Figures Patented April 24, 1973 4 Sheet,sSheet 1 FIG.

FIG. 2

ETS'UZO 'YoKoy M and YASUYA OONO,

ubmm Patented April 24, 1973 4 Sheets-Sheet 2 FIG. 4

ETSUZO YOKOYAMA and YAsUYA' OONO,

INVENTOR s ATTORNEYS Patented April 24,1 3,729,601

- 4 Sheets-Sheet 3 ETS-UZO YOKOYAMA and YASUYA 0on0,

1 ,INVENTOR s ATTORNEY S @Mmw -Patentcd April 24,1913 3,729,601

4 Sheets-Sheet 4 ETSUZO YOKOYAMA and YASUYA' OONO,

1NVENTO ATTORNEY s BACKGROUND OF THE INVENTION This invention relates to a time-setting device or a socalled timer capable of automatically controlling the operating interval of radio and television receivers, alarms, and various other electrical equipment.

Time-setting devices used in combination with radio and television receivers and the like, in particular, are required to have means for connecting or disconnecting them from the power line after a predetermined length of time, and means for connecting or disconnecting them after as long as several hours or more. Desirably, they may be further equipped with a built-in alarm to be set off after a desired period of time.

The conventional time-setting devices or timers combining all such functions have inevitably had a number of operative shafts or their equivalents to perform the respective functions, thereby giving rise to erroneous handling on the part of the user. They have also necessitated complex and bulky mechanisms which result in increased manufacturing costs and frequent troubles during operation.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a time-setting device of a simple and inexpensive construction, which requires one operative shaft for automatically connecting or disconnecting the power line after a desired length of time.

Another object of the invention is to provide a timesetting device having a pair of operative shafts for automatically connecting or disconnecting the power line after a desired length of time.

Another object of the invention is to provide a timesetting device for automatically connecting and then disconnecting the power line at desired time intervals.

A further object of the invention is to provide a time setting device for automatically disconnecting and reconnecting the power line at desired time intervals. According to the present invention, briefly summarized, there is provided a time-setting device comprising an on-off switch shiftable between the two conditions by an operative member provided thereto, and a setting shaft rotatably supported adjacent the operative member. A first cam is fixedly mounted on the setting shaft, the first cam having a first and a third peripheral range for engagement with the operative member, in which the on-off switch is turned into a prescribed one of its two conditions, and a second and a fourth peripheral range for engagement with the operative member in which the on-off switch is turned into the other condition, the second peripheral range being disposed adjacent the first peripheral range, and the third peripheral range being disposed adjacent the fourth peripheral range. A clock mechanism including a gear rotated in step with the lapse of time is also provided and a second cam is fixedly mounted on the setting shaft so as to be sel'ectively engaged with the gear of the clock mechanism depending upon the peripheral range of the first cam engaged with the operative member, the first cam being conveyed with the rotation of the gear when the second cam is engaged therewith. The invention further includes means for selectively imparting rotation to the first cam depending upon the peripheral range of the first cam engaged with the operative member.

The characteristic features of this invention are set foth with particularity in the appended claims. The invention itself, however, both as to its construction and mode of operation, together with the various other objects and advantages thereof, will be best understood from the following description of a preferred embodiment illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a perspective view of a digital clock embodying the novel concepts of the present invention;

FIG. 2 is a perspective view showing the essential parts of the digital clock of FIG. 1;

FIG. 3 illustrates a display board on the digital clock of FIG. 1;

FIG. 4 is a sectional view taken along the plane of line IV-IV in FIG. 1;

FIG. 5 is a view by way of explanation of the construction and operation of a first cam in the digital clock of FIG. 1;

FIG. 6 is a view by way of explanation of the construction and operation of a second cam in the digital clock of FIG. 1;

FIG. 7 is a view by way of explanation of the construction and operation of an alarm in the digital clock of FIG. 1; and

FIG. 8 is a view by way of explanation of the construction and operation of a torque cam in the digital clock of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION knob 17 on its front-panel side. Extending below the first setting shaft 16, a second setting shaft 18 is similarly rotatably supported between the front panel 11 and the back panel 13 and is fixedly provided with a knob 19 on its front-panel side. correspondingly to these knobs l7 and 19, a display board 20 is provided on the front panel 11.

A first cam 21 is fixedly mounted on the first setting shaft 16 between the front panel 1 l and the back panel 13. Also between the front panel ill and the back panel 13 the first setting shaft 116 rotatably supports a bushing 23, while this bushing is securely provided with a gear 22 and is further frictionally engaged with a ratchet wheel 25 which is urged thereto by spring means. The ratchet wheel 25 is partially coveredwith a mask 24 which is secured to the right-hand panel 12 and held by the bushing 23.

A second cam 26 is securely mounted on the first setting shaft 16 between the front panel 11 and the 12 and the partition 15 so as to engage the second cam 26. On the back of the second cam 26 a torque cam 29 is secured to the first setting shaft 16. A turnable arm 30 is supported at one end by the back panel 13 and, at the other end, engages the periphery of the torque cam 29 to actuate the same. This arm is to be turned by the force of a spring 31 connected to the back panel 13 at one end and to the arm 30 at the other end.

Rotatably supported between the front panel 12 and the back panel 13, a shaft 32 is geared to an output shaft of a synchronous motor 43 so as to rotate at predetermined speed with the lapse of time. A gear 33 mounted on the shaft 32is meshed with the aforesaid gear 22 in order to convey prescribed revolving force to the latter according to the lapse of time. A third cam 34 is provided between the front panel 1 1 and the back panel 13 so as to be rotatably on the second setting shaft 18. This third cam is formed with an angular projection 34a on its back, the projection being sloped on one side thereof. A bushing 35 is rotatable on the second setting shaft 18 and is secured with a gear 36 which is meshed with the gear 33 and which is engaged with a slide plate 39 and the third cam 34. The gear 36 is formed with an opening 36a so as to receive the projection 34a of the third cam 34 as desired. The bushing 35 is fixedly provided with a circular flange 37 on its back-panel side. Between this flange 37 and the back panel 13 a spring 38 is provided to the second setting shaft 18 as illustrated.

Movably supported between the front panel 11 and the back panel 13, the aforementioned slide plate 39 is engageable with the gear 36 and a projection 48a of the first cam 21 to block the clockwise turn of the first cam at predetermined position. This slide plate 39 is pulled toward the back panel 13 by a spring 40 extending between the slide plate and the back panel. An on-off switch 41 is provided on the right-hand panel 12 so as to engage the first cam 21 through an opening 42 of the right-hand panel 12 and hence to connect or disconnect the electric circuit from its power line. The aforesaid synchronou's motor 43 may be designed to run in synchronism with a frequency of, say,.60 Hz.

Referring to FIG. 3, the knob 17 is provided with an integral index portion 17a. in the circular track of the leading end of the index portion 17a on the display board portion 1 a, indicia OFF, where the on-off switch 41 is turned off, is marked centrally as a reference position. Other indicia may be marked at suitable positions in the counterclockwise direction of the index portion 17a, as hereinafter described by way of example. indicia ON, where the switch 41 is turned on, and AR, where the switch 41 automatically disconnects the electric circuit from the power line after a predetermined length of time, are given at positions of 30 and 60, respectively, from the aforesaid reference position. Further, in the range of 90 to 150 from the reference position, numerals O to 60 are graduated as in the drawing to denote time in minutes for operation before the automatic stop.

On the other hand, in the clockwise direction from the reference position, indicia AA for alarm purposes 'is marked at a position of 30 therefrom. in the range of 60 to 120 from the reference position, numerals 0 to 60 are graduated as in the drawing to denote time in minutes for automatic actuation (meaning that the electric circuit is automatically turned on after a predetermined length of time). Finally, indicia ON where the switch 41 may be manually turned on is marked at a position of from the indicia OFF.

The knob 19 also is provided with an integral index portion 19a. A display board portion 20b on which the leading end of the index portion 19a turns is graduated like the dial of a timepiece to represent the time.

Proceeding now to the description of the operation of the preferred embodiment of the invention in relation with FIGS. 2 and 3 in particular, the index portion 17a of the knob 17 may be turned counterclockwise and set to any desired length of time from 0 to 60 minutes on the display board portion 20a for automatic stop (meaning automatic disconnection of the electric circuit upon lapse of a predetermined length of time). In agreement with the angle of revolution of the index portion 17a, the first and second cams 21 and 26 and the torque cam 29 mounted on the first setting shaft 16 are revolved. Thereupon the first cam 21 turns on the switch 41, the second cam 26 engages the ratchet wheel 25 via the click 27, and the torque cam 29 causes the arm 30 to provide clockwise rotation to the first setting shaft 16. The ratchet wheel 25 is rotated clockwise in step with the lapse of time by the gear 33 via the gear 22 mounted on the bushing 23. As a result, the second cam 26 is rotated with the lapse of time through the click 2'7, so that the first setting shaft 16 is similarly rotated clockwise with the lapse of time. It will now be understood that the first cam 21 and the knob 17 secured to this first setting shaft are also rotated clockwise with the lapse of time.

Upon lapse of the predetermined length of time, when the index portion 17a is located on the graduation 0 on the display board portion 20a, the click 27 of the second cam 26 is disengaged from the ratchet wheel 25 by the mask 24, so that now the first setting shaft 16 is no longer rotated with the time. As long as the first cam 21 is being rotated with the time, this first cam keeps the switch 41 turned on. However, when the index portion 17a is turned to the graduation 0, the first setting shaft 16 is further rotated clockwise as the click 27 is disengaged from the ratchet wheel 25 due to the clockwise revolving force being conveyed to the first setting shaft from the torque cam 29 through the arm 30. With the clockwise rotation of the first setting shaft 16, the first cam 21, the second cam 26 and the knob 17 related therewith are turned. As the index portion 17a of the knob 17 is thus turned from the graduation 0 to the indicia AR, the projection 48a of the first cam 21 engages the slide plate 39 thereby preventing the rotation of the first cam 21. Hence the switch 41 is automatically turned off.

For automatic re-actuation upon lapse of a predetermined length of time following an automatic stop, the index portion 17a of the knob 17 is turned counterclockwise and set to a desired length of time from 0 to 60 minutes as in the precedingly described case of automatic stop. The index portion19a of the other knob 19 also is set to a desired length of time for the purpose of ire-actuation. In agreement with the angle of revolution of this knob 19, the second setting shaft 18 is turned, with the result that the third cam 34 secured thereto is turned according to the set length of time.

The gear 36, in mesh with the gear 33, is being rotated with the time, so that its opening 36a engages the projection 34a of the third cam 34 after the predetermined length of time. The gear 36 is now urged toward the front panel 11 by the froce of the spring 38 through the flange 37 and the bushing 35. The slide plate 39 engaged with the gear 36 also is pressed forward so that the projection 48a of the first cam 21 is now disengaged.

At the automatic stop, the first cam 21 engages the slide plate 39 and is temporarily prevented from rotation, as already mentioned in connection with the indicia AR. Since, also as previously mentioned, the slide plate 39 is disengaged from the projection 48a of the first cam 21 upon lapse of the length of time precedingly set by the knob 19, the first setting shaft 16 is rotated clockwise by the arm 30 through the torque cam 29. By this clockwise rotation of the first setting shaft 16, the index portion 17a of the knob 17 turns on the display board portion 20a from the indicia AR to the indicia ON, when the arm 30 no longer conveys rotation to the torque cam 29. Thus the index portion 17a is retained at the indicia ON, and the first cam 21 is engaged so as to turn on the switch 41. In this manner is the on-off switch turned on after the predetermined length of time.

It will be noted at 34b of FIG. 4 that the projection 34a of the third cam 34 is tapered toward the rotational direction of the knob 19 so that the projection may be disengaged from the opening 360 of the gear 36 as desired.

For the purpose of automatic actuation after a predetermined length of time, the index portion 17a of the knob 17 is turned clockwise and set to a desired length of time from 0 to 60 minutes. The first cam 21, the second cam 26 and the torque cam 29 which are provided to the first setting shaft 16 are then turned in step with the angle of revolution of the index portion 17a. The first cam 21 turns on the switch 41, the second cam 26 is engaged with the ratchet wheel 25 through the click 27, and the torque cam 29 causes the arm 30 to produce clockwise rotation in the first setting shaft 16. The ratchet wheel 25 is rotated clockwise with the lapse of time by the gear 33 through the gear 22. As a consequence, the second cam 26 and therefore the first setting shaft 16 are rotated clockwise with the lapse of time through the click 27. When, accordingly, the index portion 17a of the knob 17 secured to the first setting shaft 16 has been turned to the graduation 0 after the predetermined length of time, the click 27 of the second cam 26 is disengaged from the ratchet wheel 25 by the mask 24 thereby preventing the first setting shaft 16 from rotating with the lapse of time.

While the first cam 21 is being rotated with the lapse of time, it keeps the switch 41 turned off. However, as the index portion 17a is turned to the graduation 0, the click 27 is disengaged from the ratchet wheel 26 by the mask 24 as aforesaid, with the result that clockwise rotation is conveyed to the first setting shaft 16 from the arm 30 through the torque cam 29. The first cam 21, the second cam 26 and the knob 17 are turned with this clockwise rotation of the first setting shaft 16. As the index portion 17a of the knob 17 is thus turned from the graduation 0 to the indicia ON on the display board portion 20a, the arm 30 no longer rotates the first setting shaft 16 through the torque cam 29. The first cam 21, the second cam 26 and the knob 17 are thus stopped when the index portion 17a reaches the indicia ON. In this instance, the first cam 21 turns on the switch 41 thereby causing automatic actuation after the predetermined length of time.

Further, by turning the index portion 170 to the indicia AA, the first cam 21, the second cam 26 and the torque cam 29 are turned with the rotation of the first setting shaft 16. The first cam 21 turns off the switch 41. The second cam 26 is disposed at its position for en gagement with the lever 28. The torque cam 29 no longer conveys rotation to the first setting shaft 16, so that this shaft is retained with the index portion 17a on the indicia AA. Therefore, if the knob 19 is set to a desired length of time, the projection 34a of the third cam 34 is engaged with the opening 36a of the gear 36 upon lapse of that time as previously mentioned, so that the gear 36 is pressed forward by the spring 38 through the flange 37 and the bushing 35. The lever 28 is normally prevented from forward movement by the flange 37, but this flange is pressed forward upon engagement of the gear 36 with the third cam 34 after the desired length of time. The lever 28 thus released is pressed forward while in engagement with the second cam 26, whereupon the leading end of this lever is disengaged from an alarm thereby to sound the same.

When the index portion 17a of the knob 17 is at the reference position marked with the indicia OFF, the torque cam 29 does not convey rotation to the first setting shaft 16. The first cam 21 keeps the switch 41 turned off, and the second cam 26 is entirely out of engagement. It may be noted that the second cam is not engaged with any means except when the index portion 17a is in the range of the graduations 0 to 60 or on the indicia AA.

Some of the components of the present embodiment of the invention are hereinafter described in greater detail both as to their construction and operation. Referring first to FIGS. 4 and 5, the on-off switch 41 is provided with an operative member 44which keeps the switch turned on when pressed, and off when not pressed. In order to press this operative member 44 and hence to turn on the switch 41 when the index portion 17a of the knob 17 is turned counterclockwise in the range of to i.e. in the range of the graduations 0 to 60, from the aforesaid reference position on the dial board portion 20a, FIG. 3, an unindented portion 45a is formed on the circumference of a circle with a radius R1 from the center of the first cam 21. An indented portion 45b is formed on the circumference of a circle with a radius R2 from the center of the first cam 21 in order not to press the operative member 44 and hence to keep the switch 41 turned off when the index portion 17a is turned 60 in the counterclockwise direction from the reference position to the indicia AR. It is understood that the radius R1 is greater than the radius R2.

An unindented portion 45c is formed on the circumference of the circle with the radius R1 from the center of the first cam 21 in order to press the operative member 44 and hence to turn on the switch 41 when the index portion 17a is 30 in the counterclockwise direction from the reference position to the indicia ON. An indented portion 45d is formed on the circumference of the circle with the radius R2 from the center of the first cam 21 in order not to press the operative member 44 and hence to keep the switch 41 turned off when the index portion 17a is at the reference position or on the indicia OFF, when the index portion is turned 30 in the clockwise direction from the reference position to the indicia AA, and when the index portion is turned from 60 to 120 in the clockwise direction from the reference position to the range of the graduations O to 60. An unindented portion 452 is formed on the circumference of the circle with the radius R1 from the center of the first cam 21 in order to press the operative member 44 and hence to turn on the switch 41 when the index portion 17 a is turned 150 from the reference position to the indicia ON.

The first cam 21 is provided with a projection 46 tapered at 46a and 46b and having a central blunt edge at 46c. Inwardly of this projection 46 an aperture 47 is formed. On the back of the first cam 21, a disc 48 is mounted on the first setting shaft 16 and is provided with a projection 48a on its front side through the aperture 47, the projection 48a extending to approximately the same height as the aforesaid projection 46. A spring 49 is secured at one end to the first cam 21 and at the other end to the disc 48 in order to urge the projection 48a of the disc 48 to the left-hand end of the aperture 47.

The aforementioned slide plate 39 includes a portion 390 engageable with the periphery of the gear 36, and another portion 39b opposed to the front side of the first cam 21. This slide plate permits the counterclockwise rotation of the first cam 21 over the righthand tapered edge 46b and central blunt edge 460 of the projection 46 and the projection 48a of the disc 48. However, as the projection 48a is succeedingly caught by the portion 39b of the slide plate 39, further rotation of the first cam 21 is prevented. When the first cam 21 is thus stopped, its indented portion 45b is located op-' posite the operative member 44, so that the switch 44 is turned off.

As the gear 36 is pressed forward after a predetermined length of time as aforesaid, the slide plate 39 also is pressed forward through its portion 39a. As a result, its portion 39b moves out of engagement with the projection 48a, and the clockwise rotation of the first cam 21 is permitted after the predetermined length of time.

By turning the first setting shaft 16 with the knob 17 against the tensile force of the spring 49, the projection 48a of the disc 48 is subjected to the counterclockwise revolving froce from the slide plate 39. This slide plate 39 is permitted to go over the projection 48a by passing the central edge 46c of the projection 46 through its tapered edge 460. Thus, by the turn of the knob 17, the first cam 21 is permitted. to make clockwise rotation as the slide plate 39 is disengaged from the projection 48a. It is understood that the projection 48a on the front side of the first cam 21 is so positioned that the first cam 21 may be prevented from rotation when the index portion 17a of the knob 17 is turned to the inthat this bushing is rotatable on the first setting shaft 16. The mask 24 is formed with a notch 50 so that the leading end of the click 27 of the first cam 26 secured to the first setting shaft 16 may engage the ratchet wheel 25 when the index portion 17a of the knob 17 is turned from to 150 L the counterclockwise direction from the reference position on the display board portion 20a to the range of the graduations 0 to 60. Simiiarly, the mask 24 is formed with another notch 51 so that the leading end of the click 27 may engage the ratchet wheel 25 when the index portion 17a is turned from 60 to in the clockwise direction from the reference position on the display board portion 20a to the range of the graduations 0 to 60.

As best shown in FIG. 4, a flange 52 is fixedly provided to the bushing 23 on the back of the ratchet wheel 25. Between this ratchet wheel and the mask 24, a substantially dish-shaped spring 53 is attached to the bushing 23 to urge the ratchet wheel 25 against the flange 52 and hence to convey the rotation of the bushing 23 to the ratchet wheel. The click 27 having a tumable leading end is supported by the second cam 26 so as to be urged against the periphery of the mask 24 by a spring 54 securely provided to the second cam 26. The lever 28 is supported at its left-hand end 55a by the partition 15 and at its right-hand end 55b by the righthand panel 12, one end 55c thereof being coupled with one end of a spring 56a the other end of which is secured to the back panel 13. The lever 28 is formed with a projection 56 which is urged against the second cam 26 at 26a by means of a spring.

A corresponding depression 57 is formed at 26a of the second cam 26 so as to receive the projection of the lever 28. The flange 37 on the bushing 35 mounted on the second setting shaft 18 is provided to prevent the projection 56 0f the lever 28 from engagement with the depression 57 of the second cam 26. The synchronous motor 43 includes an iron core 58 and an iron member 59 which may be bolted at 60 to the iron core 58. A hammer61 has one end connected to the right-hand panel 12. The other end, or a head 62 of this hammer is disposed opposite the iron member 59 witha predetermined spacing therebetween.

The relative locations of the lever 28, the iron member 59, and the hammer 58 are illustrated in FIG. 7. The lever 28 has its one end 63 bent at a right angle toward the back panel 13. The iron member 59 and the head 62 of the hammer 61 is brought closer than the aforesaid predetermined spacing only when the projection of the lever 28 is engaged with the corresponding depression 57 of the second cam 26. At other times the end 63 of the lever 28 keeps the iron member 59 and the head 62 of the hammer 61 at more than the predetermined spacing. When the iron member 59 and the hammer head 62 are within the predetermined spacing, the iron member 59 is magnetized by the iron core 58 at the power frequency and thus attracts the hammer head 62.'The hammer head pounding upon the iron member in this manner produces the desired alarming sound.

It may be noted in connection with FIG. 6 that the clockwise rotation of the gear 22, FIG. 4, which proceeds in step with the lapse of time as aforesaid, is conveyed to the bushing 23 on the first setting shaft 16, and thence to the ratchet wheel 25 which is indirecly secured to the bushing 23 by the spring 53 through the flange 52. Whenthe index portion 17a is turned to the range of the graduations to 60 on the display board portion 20a by the knob 17 provided to the first setting shaft 16, the click 27 together with the second cam 26 is turned to the corresponding one of the notches 59 and 51 for engagement with the ratchet wheel 25. Upon engagement of the click 27 with the ratchet wheel 25, the second cam 26 is conveyed with the motion of the latchet wheel, which is being rotated clockwise with the lapse of time. This clockwise rotation of the second cam 26 is transmitted through the first setting shaft 16 to the first cam 21, which then is also rotated clockwise with the lapse of time.

The clockwise rotation with the lapse of time of the first setting shaft 16 is, of course, accompanied by that of the index portion 17a of the knob 17. As this index portion is succeedingly turned to the graduation 0, the click 27 is-disengaged from the ratchet wheel 25 by the mask 24 as previously mentioned. The second cam 26 is now released, and the first setting shaft 16 is further rotated by the aforesaid means. Since the ratchet wheel 25 is secured to the bushing 23 by being frictionally engaged between the spring 53 and the flange 52, the knob 17 can be turned in a desired direction even when the click 27 is engaged with the ratchet wheel 25. Further, the click may be automatically disengaged therefrom by turning the knob to the indicia AR.

Referring now to both FIGS. 4 and 8 in order to describe the construction and operation of the torque cam 29 mounted on the first setting shaft 16, the arm 30 turnably-supported by pin 64 at the back panel 13 carries at its free end a roller 45 which rolls on the torque cam 29. The spring 31 is connected at one end to the right-hand panel 12 and at the other end to the arm 30 between the roller 65 and the pin 64, thereby tending to turn the arm 30 toward the first setting shaft 16. The torque cam 29 is equipped with a curved portion 290 to support the roller 65 when the index portion 17a of the knob 17 is turned from 60 to 150 counterclockwise from the reference position on the display board portion 20a to the range of the indicia AR to the graduation 60. This curved portion 29a is so shaped that its radius of revolution increases toward the clockwise direction. A depression 2% receives the roller 65 when the index portion 17a is turned 30 in the counterclockwise direction from the reference position to the indicia ON. Another depression 290 receives the roller 65 when the index portion 17a is at the reference position marked with the indicia OFF. A further depression 29d similarly receives the roller 65 when the index portion 17a is turned 30 in the clockwise direction from the reference position to the indicia AA. A curved portion 29e, shaped in substantial accordance with the foregoing curved portion 29a, sup ports the roller 65 when the index portion 17a is turned clockwise from 60 to 150 from the reference position to the range of the graduation 60 to the indicia ON.

When the index portion 17a of the knob 17 is in the range of the indicia AR to the graduation 60, and, therefore, when the roller 65 is in contact with the curved portion 290, the said roller is pressed toward the first setting shaft 16 by the spring 31 coupled with the arm 30. Thus the roller is urged toward that part of the curved portion 29a which has a smaller radius, so that the torque cam 29 is subject to the force tending to turn the same in the clockwise direction. Such clockwise rotation is conveyed to the first cam 21 through the first setting shaft 16. Accordingly, as far as the index portion 17a is in the range of the indicia AR to the graduation 60, the index portion is always subjected to the force tending to turn the same clockwise, that is toward the indicia AR. The same revolving force causes the operative member 44 of the on-off switch 41 to engage the unindented portion 450 of the first cam 21 after moving out of engagement with the unindented portion 45a and through the indented portion 45b.

Similarly, when the index portion 17a of the knob 17 is in the range of the graduation 60 to the indicia ON in the clockwise direction, the roller 65 is in contact with the other curved portion 2%, so that the first cam 21 turns toward the indicia ON. In this case the operative member 44 shifts out of engagement with the indented portion 45d of the first cam 21 and into engagement with the unindented portion 45e. It will be understood that the first setting shaft 16 is not actuated by the roller 65 when the roller 65 is in contact with the torque cam 19 at its 29b, 29c or 29d, or when the index portion 17a is on the indicia ON, OFF or AA.

Referring back to FIG. 4 in particular, numeral 66 indicates a shaft rotatably supported between the righthand panel 12 and the back panel 13 and geared to the output shaft of the synchronous motor 43, FIG. 1, so as to be rotated at a predetermined speed. A worm gear 67 is mounted on the shaft 66 and is meshed with another gear 68 which is rotatably supported between the front panel 11 and the back panel 13 and which is mounted on the shaft 32 like the aforementioned gear 33. Hence the rotation of the synchronous motor output shaft is conveyed to the shaft 66, which then rotates at synchronous speed, and thence to the gear 33 through the worm gear 66 and the gear 68. Being further meshed with the gears 22 and 36, the gear 33 causes these gears to rotate at synchronous speed in step with the lapse of time.

Finally, for the purpose of automatic actuation followed by an automatic stop in the above described embodiment of this invention, the first cam 21 may be formed with projections corresponding to the aforesaid projections 46 and 48a. The rotation of the first cam 21 may be temporarily stopped by the slide plate 39. By releasing this slide plate after a predetermined length of time by the engagement of the cam 34 and the gear 36, the first cam 21 may be turned by the torque cam 29 so as to turn off the switch 41. Other details of construction and operation are substantially the same in the previously described case of an automatic stop followed by automatic re-actuation.

Although the present invention has been shown and described in the foregoing in terms of a preferred embodiment thereof, it will be understood that the invention itself is not to be limited thereto but includes obvious and reasonable equivalents within the skill of those in the art. For instance, the first cam 21, the second cam 26, the third cam 34 and the torque cam 29 may be provided in various forms other than those illustrated in the attached drawings without departing from the scope of the invention herein disclosed.

We claim:

1. A time-setting device comprising an on-off switch having an operative member and defining an on or off condition by shifting said operative member; a setting shaft rotatably supported adjacent said operative member; a first cam fixedly mounted on said setting shaft, said first cam having a first and third peripheral range therearound for engagement with said operative member for switching said on-off switch to the on condition, and' a second and fourth peripheral range therearound for engagement with said operative member for switching said on-off switch to the off condition, said second peripheral range being disposed adjacent said first peripheral range, and said third peripheral range being disposed adjacent said fourth peripheral range; a clock mechanism including a gear rotated in step with the lapse of time; a second cam fixedly mounted on said setting shaft, said second cam engaging said gear of said clock mechanism when said first or fourth peripheral range of said first cam is engaged with said operative member, whereby said first cam is conveyed with the rotation of said gear during the engagement of said second cam with said gear; and means for imparting rotation faster than the rotation of said clock mechanism gear on said first cam when the engagement of said second cam with said clock gear has finished, thereby changing the engagement of said first or fourth range of said first cam with said operative member to said second or third range, respectively.

2. A time-setting device according to claim 1 in which said second cam is conditionally engaged with said gear of said clock mechanism when a setting range of said first or fourth peripheral range of said first cam is engaged with said operative member.

3. A time setting device according to claim 1 in which means for imparting rotation on said first cam is engaged with said second cam for rotating said first cam.

4. A time-setting device according to claim 1, further comprising a ratchet wheel rotatable on said setting shaft while. in engagement with said gear of said clock mechanism, said ratchet wheel being engaged with said second cam to convey its rotation to said first cam when said first cam is engaged with said operative member at its first and at its fourth peripheral range.

5. A time setting device comprising an on-off switch having an operative member and defining an on or off condition by shiftirig said operative member; a setting shaft rotatably supported adjacent said operative condition, said second peripheral range being disposed between said first and said thrid peripheral ranges; a clock mechanism including a gear rotated in step with the lapse of time; a second cam fixedly mounted on said setting shaft, said second cam engaging said clock mechanism gear when said first peripheral range of said first cam is engaged with said operative member, thereby said first cam being conveyed with the rotation of said gear during the engagement of said second cam with said gear means for imparting rotation faster than the rotation of said clock gear on said first cam when the enga ement of said second cam with said clock gear has een finished, thereby changing the engagement of said first range of said first cam with said operative member to said third range via said second range; stop means adjacent said first cam for stopping the rotation of said first cam when the same is engaged with said operative member at its second peripheral range; and time-setting means engaging said stop means after a predetermined length of time and thereby permitting said first cam to be rotated by said means for imparting rotation thereto.

6. A time-setting device according to claim 5 in which said second cam is engaged with said gear of said clock mechanism when a setting range of said first peripheral range of said first cam is engaged with said operative member.

7. A time setting device according to claim 5 in which means for imparting rotation on said first cam is engaged with said second cam for rotating said first cam.

8. A time-setting device according to claim 5, further comprising a ratchet wheel rotatable on said setting shaft while in engagement with said gear of said clock mechanism, said ratchet wheel being engaged with said second cam to convey its rotation to said first cam when said first cam is engaged with said operative member at its first peripheral range. 

1. A time-setting device comprising an on-off switch having an operative member and defining an on or off condition by shifting said operative member; a setting shaft rotatably supported adjacent said operative member; a first cam fixedly mounted on said setting shaft, said first cam having a first and third peripheral range therearound for engagement with said operative member for switching said on-off switch to the on condition, and a second and fourth peripheral range therearound for engagement with said operative member for switching said on-off switch to the off condition, said second peripheral range being disposed adjacent said first peripheral range, and said third peripheral range being disposed adjacent said fourth peripheral range; a clock mechanism including a gear rotated in step with the lapse of time; a second cam fixedly mounted on said setting shaft, said second cam engaging said gear of said clock mechanism when said first or fourth peripheral range of said first cam is engaged with said operative member, whereby said first cam is conveyed with the rotation of said gear during the engagement of said second cam with said gear; and means for imparting rotation faster than the rotation of said clock mechanism gear on said first cam when the engagement of said second cam with said clock gear has finished, thereby changing the engagement of said first or fourth range of said first cam with said operative member to said second or third range, respectively.
 2. A time-setting device according to claim 1 in which said second cam is conditionally engaged with said gear of said clock mechanism when a setting range of said first or fourth peripheral range of said first cam is engaged with said operative member.
 3. A time setting device according to claim 1 in which means for imparting rotation on said first cam is engaged with said second cam for rotating said first cam.
 4. A time-setting device according to claim 1, further comprising a ratchet wheel rotatable on said setting shaft while in engagement with said gear of said clock mechanism, said ratchet wheel being engaged with said second cam to convey its rotation to said first cam when said first cam is engaged with said operative member at its first and at its fourth peripheral range.
 5. A time setting device comprising an on-off switch having an operative member and defining an on or off condition by shifting said operative member; a setting shaft rotatably supported adjacent said operative member; a first cam fixedly mounted on said setting shaft, said first cam having a first and third peripheral range therearound for engagement with said operative member for switching said on-off switch to one of its two conditions, and a second peripheral range therearound for engagement with said operative member for switching said on-off switch to said other condition, said second peripheral range being disposed between said first and said thrid peripheral ranges; a clock mechanism including a gear rotated in step with the lapse of time; a second cam fixedly mounted on said setting shaft, said second cam engaging said clock mechanism gear when said first peripheral range of said first cam is engaged with said operative member, thereby said first cam being conveyed with the rotation of said gear during the engagement of said second cam with said gear ; means for imparting rotation faster than the rotation of said clock gear on said first cam when the engagement of said second cam with said clock gear has been finished, thereby changing the engagement of said first range of said first cam with said operative member to said third range via said second range; stop means adjacent said first cam for stopping the rotation of said first cam when the same is engaged with said operative member at its second peripheral range; and time-setting means engaging said stop means after a predetermined length of time and thereby permitTing said first cam to be rotated by said means for imparting rotation thereto.
 6. A time-setting device according to claim 5 in which said second cam is engaged with said gear of said clock mechanism when a setting range of said first peripheral range of said first cam is engaged with said operative member.
 7. A time setting device according to claim 5 in which means for imparting rotation on said first cam is engaged with said second cam for rotating said first cam.
 8. A time-setting device according to claim 5, further comprising a ratchet wheel rotatable on said setting shaft while in engagement with said gear of said clock mechanism, said ratchet wheel being engaged with said second cam to convey its rotation to said first cam when said first cam is engaged with said operative member at its first peripheral range. 